It is well known that through rotating a tubing string in an oil well, the wear that typically occurs on the inside surface of the tubing string caused by sucker rod movement can be reduced or more evenly distributed around the interior surface of the string, thereby significantly extending the life of the string. A variety of different devices have been proposed by others in order to rotate the tubing string. Typically, such devices, or rotators as they are commonly known, are bolted or otherwise attached to the top of an oil well and connected in some manner to the tubing string to cause the string to rotate. In some instances the tubing string may be hung directly from the rotator, while in others a hanging apparatus may effectively hang the tubing string from the well casing. The hanging device would then most often be engaged by a rotator to turn the string.
While such prior art devices are relatively effective in distributing wear around the interior surface of the tubing string, there is little or no standardization of the size of the casing bowls that tubing hangers fit into. There is therefore a need for a wide variety of different tubing string hangers and rotators to match the size of the various different casing bowls that are used. Furthermore, the design of present rotators necessitates that they be completely removed from the oil well in order to withdraw the tubing string, or to remove the downhole pump for servicing or replacement. In many cases the tubing string of an oil well must be pulled as often as every two months in order to repair worn parts or leaks, or to service the pump. Removing the rotator from the wellhead in order to pull the string and the pump increases the amount of labour and equipment required for servicing the well, and also extends the down-time of the well and results in further lost production.